Strength is used in numerous ways to describe someone’s physical as well as mental abilities. We often draw a notion of whether this person is strong based on their physique. This ability continuously comes within thoughts as we meet, talk or just observe different people. This may sound strange, but it happens more often than we pay attention to.
So why do we think about strength so much? The short answer is evolution — as stronger individuals had a greater probability of survival. Though most of us are no longer hunting for food in the savanna but simply staking out deals of a local supermarket, the genes for survival have undoubtedly been passed on to us from ancestors; including the desire to be stronger.
Let’s take a look at physical strength as a biomotor ability — maximal force a muscle can generate — and what does it take to become stronger.
Stronger — Relative vs. Absolute Strength
A number of factors exist that play a role in who we are and what we can do on a physical scale. Things like: age, sex, body style, height, hormonal disposition, genetics, all contribute to a unique formula of what makes each of us special, and strong in a personalized way. Strength is simply an ability to exert force. Depending on the specific training method practiced, the type of strength will differ.
For example, a young boy or girl with low body weight, capable of doing many pull ups and push up possess what is referred to Relative Strength. Now, a professional strong man or a powerlifter who can pull a semi-trailer or squat 400 kg (900 lbs) is very strong indeed, but his strength is categorized as Absolute Strength.
When strength is referenced to person’s body weight, it has a Relative value. The maximum amount of force a person is able to produce, regardless of their weight class, is the Absolute kind. Regardless of your goal, relative or absolute strength increase, you first need to build muscle.
We are all aware that muscle contracts, producing force that pushes or pulls something. But how does this happen, and how can we become stronger — push or pull more weight?
Skeletal muscle consist of long cells known as muscle fibers. Inside each muscle fiber, structural compound and organelles produce the actual contractions, and generate energy necessary for such activity. These include myofibrils, long structural tubes, which contain repeated sections of contractile proteins (actin and myosin). This repeated portion within myofibril is referred to as sarcomere.
Within sarcomere, proteins actin and myosin overlap each other, cross bridge and slide against each other shortening the sarcomere structure, thus creating a small contraction. Hundreds to thousands of these tiny sarcomere shortenings take place within muscle tissue, producing a bigger contraction that is seen when we develop any kind of movement or balance. Furthermore, the muscle cells contain internal energy storages of sugar (glycogen) and fat (intramuscular trycglycerides – IMTGs) as well as oxygen attached to myoglobin; all which are required for muscular activity.
Produced force depends on the number of muscle cells — muscle fibers working together. The passage to greater strength is simply to increase the size of muscle fibers. This results in a larger cross-sectional area of the cell itself, increasing the number of actin and myosin filaments.
Hypertrophy — Muscle building
As part of our adaptation process to training, the body undergoes different types of growth or hypertrophy. To improve strength, we need to increase muscle mass. Both of these entities are connected to each other in order to generate force. As mentioned before, the cross-sectional area of the muscle fiber gets bigger as a response to strength training. Bigger muscle results in stronger contractions and the ability to lift more weight, and/or for longer periods of time.
(1) fiber hyperplasia which is an increase in the number of muscle cells — aka fibers (fibers grow in number, multiply) and
(2) fiber hypertrophy — in particular myofibrillar (aka sarcomere) hypertrophy is the enlargement of cross-sectional areas of individual fibers (fibers grow in size, get bigger). Along with sarcoplasmic hypertrophy which increases the volume of sarcoplasmic fluid resulting in greater glycogen and myoglobin within that fiber.
Fiber hyperplasia is still a fairly new research area where human and animal results are often inconsistent to generate a model process. Fiber hypertrophy on the other hand, has been extensively researched and documented as an occurring physiological process. Some research states that both fiber hyperplasia and hypertrophy take place during strength training protocols. But, exact contribution of each mechanism is inconsistent and appears to differ from person to person, or animal to animal. Due to the undeveloped practical application for fiber hyperplasia, we’ll focus our discussion to improve fiber hypertrophy.
This type of hypertrophy involves increases in size of the sarcoplasmic fluid and non-contractile proteins. These attributes assist in the overall function of the muscle cell but do not directly participate in force production. Sarcoplasm also contains glycosomes — which are storage granules of glycogen and myoglobin. During high-intensity or strength-endurance training, the glycosomes play an important role in supplying energy to sustain such activities. In women, strength training has been noted to increase intramuscular triglyceride content. More fat within the muscle is not a bad thing, but simply an adaptation to preferred substrate and energy pathway (we discuss this topic further in Metabolic Differences within Genders article).
This type of hypertrophy involves the synthesis of contractile proteins. An increase in filament density of actin and myosin proteins occurs in relation to the cross-sectional area of the muscle cell. As a result, the cross-sectional area of fiber increases resulting in a muscle cell capable of generating more force. Myofibrillar hypertrophy is the preferred result and the strategic goal of many strength training programs.
Muscular Balance — you get some, you lose some
There are a number of discussions about muscle building (anabolism) and breakdown (catabolism). Many of such talks focus on methods to maximize muscle building and limit its degradation. The reality being, muscle cell follows the same principles as other cells within your body, but with a few differences.
- Muscle cell is a specialized cell containing many nuclei (a typical cell has only 1 nucleus) designed to perform a specific function.
- Generating a muscle cell takes significant processes, materials, and energy.
Hence, body does not replace muscle cells as often as some more generalized body cells (for example epithelial cells within your skin).
As muscle is continuously utilized throughout the day, parts of it — especially contractile proteins — get damaged (micro-tears). This normal wear and tear contribute to the overall amalgamation of muscular breakdown that needs to be repaired. Some muscle cells, eventually need to be replaced altogether, therefore contributing to the overall catabolic process. Strength training also contributed to muscle degradation — through an increase in force production by engaging more contractile filaments within muscle fibers. During physical training, some of the protein does catabolize into amino acids for energy supplementation, in order to maintain activity and continue to produce force.
The upside of any catabolism experienced during a training session is that it creates an environment referred to as super-compensation. This increases the need for a cell to adapt, by growing its contractile portions (myofibrils) — increasing cross-sectional areas during rest periods. Majority of muscle protein hypertrophy takes place during recovery periods between training sessions. During exercise, the amount of energy inside your body often determines the overall balance between protein breakdown (catabolism) and synthesis (anabolism).
To maximize muscular hypertrophy, we need to create an environment through exercise routines by steadily elevating mechanical overload that generates significant metabolic stress. This metabolic stress increases protein catabolism during an exercise session, and raises super-compensation during recovery period. Let’s take a look at the following intensities and how they affect overall protein synthesis.
Loads of 1-3RM:
Maximum loads generate greatest physical efforts and cause significant damage to muscle fibers. Such heavy weight can only be performed for one or two repetitions thus resulting in overall low mechanical work.
Loads of 5-10RM:
The selected intensities are lower, resulting in greater volume and overall mechanical work. Due to longer duration of each exercise set, there is a noticeable accumulation of muscular micro-tearing and metabolic stress.
Loads of 25+RM:
Weight selections in this category are low generating long exercise durations. These lengthy sets produce high mechanical output, but low levels of muscular micro-damage (due to very light loads / intensities).
Pure strength development is specific and lays through the road of high intensity. 1-3RM loads will challenge your body and your mind. This training style develops not only your muscular system by nervous one as well, and will be covered in later articles. For the purpose of strength training pertaining to muscular growth, the exercise regiments are favoured that yield significant metabolic stress and protein catabolism. Selecting loading in the range of 5-10RM creates an ideal combination of both intensity and mechanical work output to favour super-compensation during recovery.
Strength is the biomotor ability that has shaped mankind into a dominant species on this planet. Admiring strength is a normal occurrence as our genome inherently desires this trait for greater fitness and survival.
Depending on the style of exercise, the body adapts and develops specific styles of strength. Bodyweight exercises produce greater relative strength, and lifting maximal weights increases absolute strength values.
Everything happens inside the muscle cell where long thin strings of repeated portions containing contractile proteins slide and pull against each other. This action shortens overall contractile element, producing a contraction. Size is related to strength and specific training often increases both values.
There are two types of hypertrophy that grow muscle — an increase of contractile proteins diameter (myofibrillar hypertrophy) and increase of cell’s sarcoplasm and non-contractile proteins (sarcoplasmic hypertrophy). Recent studies have suggested that muscle can grow its contractile proteins in two ways:
- becoming bigger through an increase in diameter / cross-sectional area, and
- increasing in the number of muscle fibers — known as fiber hyperplasia.
For muscular hypertrophy, training with sub-maximal loads of 5-10RM generates best conditions of mechanical work and muscular micro-damage. Such protocols create substantial metabolic stress generating greater super-compensation resulting in more functional muscle. For targeted training be sure to learn more about our Stronger Leaner Faster Training Book.